It was basically a contest of Power in ancient times, whereby two men would battle against each other, to determine who was stronger.

This was the foundation that all later developments in Sumou were based on.

This is also the predicament that determines the goal of Sumou. The key to always remember that the meaning of Sumou is to ascertain your supremacy due to superior Power. I.e. the goal of Sumou is to conquer the Aite by being more Powerful than he is.

This determines the philosophical precepts associated with the Meaning of Good Sumou vs. Bad Sumou. Though many things are allowed in Sumou, e.g. Atarihenka and so, they are valueless, because when utilizing them you defeat the purpose of Sumou as a Trial of Power.

In ancient times the precursor of Sumou, before rules were developed, was basically a rough combat, designed to compare the combatants' Power.